Remove all descendant views from AXAuraObjCache when a view is removed.

ui/views/accessibility/ax_aura_obj_cache_unittest.cc

Index: ui/views/accessibility/ax_aura_obj_cache_unittest.cc
diff --git a/ui/views/accessibility/ax_aura_obj_cache_unittest.cc b/ui/views/accessibility/ax_aura_obj_cache_unittest.cc
new file mode 100644
index 0000000000000000000000000000000000000000..0013e96196a1bf2505481f0ce3393b9f50d62d6a
--- /dev/null
+++ b/ui/views/accessibility/ax_aura_obj_cache_unittest.cc
@@ -0,0 +1,57 @@
+// Copyright 2016 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "ui/views/accessibility/ax_aura_obj_cache.h"
+#include "ui/views/test/widget_test.h"
+
+namespace views {
+namespace test {
+
+namespace {
+
+// This class can be used as a deleter for scoped_ptr<Widget>
+// to call function Widget::CloseNow automatically.
+struct WidgetCloser {
+  inline void operator()(Widget* widget) const { widget->CloseNow(); }
+};
+
+using WidgetAutoclosePtr = scoped_ptr<Widget, WidgetCloser>;
+}
+
+class AXAuraObjCacheTest : public WidgetTest {
+ public:
+  AXAuraObjCacheTest() {}
+  ~AXAuraObjCacheTest() override {}
+};
+
+TEST_F(AXAuraObjCacheTest, TestViewRemoval) {
+  WidgetAutoclosePtr widget(CreateTopLevelPlatformWidget());
+  View* parent = new View();
+  widget->GetRootView()->AddChildView(parent);
+  View* child = new View();
+  parent->AddChildView(child);
+
+  AXAuraObjCache* cache = AXAuraObjCache::GetInstance();
+  AXAuraObjWrapper* ax_widget = cache->GetOrCreate(widget.get());
+  ASSERT_NE(nullptr, ax_widget);
+  AXAuraObjWrapper* ax_parent = cache->GetOrCreate(parent);
+  ASSERT_NE(nullptr, ax_parent);
+  AXAuraObjWrapper* ax_child = cache->GetOrCreate(child);
+  ASSERT_NE(nullptr, ax_child);
+
+  // Everything should have an ID, indicating it's in the cache.
+  ASSERT_GT(cache->GetID(widget.get()), 0);
+  ASSERT_GT(cache->GetID(parent), 0);
+  ASSERT_GT(cache->GetID(child), 0);
+
+  // Removing the parent view should remove both the parent and child
+  // from the cache, but leave the widget.
+  widget->GetRootView()->RemoveChildView(parent);
+  ASSERT_GT(cache->GetID(widget.get()), 0);
+  ASSERT_EQ(-1, cache->GetID(parent));
+  ASSERT_EQ(-1, cache->GetID(child));
+}
+
+}  // namespace test
+}  // namespace views